View source: R/compute_hydat_peak_frequencies.R
compute_hydat_peak_frequencies  R Documentation 
Performs a volume frequency analysis on annual peak statistics (instantaneous minimums or maximums) extracted from
HYDAT. Calculates statistics from all years, unless specified. The data
argument is not available. Analysis
methodology replicates that from HECSSP. Returns a list of tibbles
and plots.
compute_hydat_peak_frequencies(
station_number,
use_max = FALSE,
use_log = FALSE,
prob_plot_position = c("weibull", "median", "hazen"),
prob_scale_points = c(0.9999, 0.999, 0.99, 0.9, 0.5, 0.2, 0.1, 0.02, 0.01, 0.001,
1e04),
fit_distr = c("PIII", "weibull"),
fit_distr_method = ifelse(fit_distr == "PIII", "MOM", "MLE"),
fit_quantiles = c(0.975, 0.99, 0.98, 0.95, 0.9, 0.8, 0.5, 0.2, 0.1, 0.05, 0.01),
start_year,
end_year,
exclude_years,
plot_curve = TRUE
)
station_number 
A character string vector of seven digit Water Survey of Canada station numbers (e.g. 
use_max 
Logical value to indicate using maximums rather than the minimums for analysis. Default 
use_log 
Logical value to indicate logscale transforming of flow data before analysis. Default 
prob_plot_position 
Character string indicating the plotting positions used in the frequency plots, one of 
prob_scale_points 
Numeric vector of probabilities to be plotted along the X axis in the frequency plot. Inverse of
return period. Default 
fit_distr 
Character string identifying the distribution to fit annual data, one of 
fit_distr_method 
Character string identifying the method used to fit the distribution, one of 
fit_quantiles 
Numeric vector of quantiles to be estimated from the fitted distribution.
Default 
start_year 
Numeric value of the first year to consider for analysis. Leave blank or set well before start date (i.e.

end_year 
Numeric value of the last year to consider for analysis. Leave blank or set well after end date (i.e.

exclude_years 
Numeric vector of years to exclude from analysis. Leave blank or set to 
plot_curve 
Logical value to indicate plotting the computed curve on the probability plot. Default 
A list with the following elements:
Freq_Analysis_Data 
Data frame with computed annual summary statistics used in analysis. 
Freq_Plot_Data 
Data frame with coordinates used in frequency plot. 
Freq_Plot 
ggplot2 object with frequency plot 
Freq_Fitting 
List of fitted objects from fitdistrplus. 
Freq_Fitted_Quantiles 
Data frame with fitted quantiles. 
compute_frequency_analysis
## Not run:
# Working examples (see arguments for further analysis options):
# Compute an annual peak frequency analysis using default arguments (instantaneous lows)
results < compute_hydat_peak_frequencies(station_number = "08NM116",
start_year = 1980,
end_year = 2010)
# Compute an annual peak frequency analysis using default arguments (instantaneous highs)
results < compute_hydat_peak_frequencies(station_number = "08NM116",
start_year = 1980,
end_year = 2010,
use_max = TRUE)
## End(Not run)
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.